Impacts of Outdoor Air Pollution on Human Semen Quality: A Meta-Analysis and Systematic Review

Table 1

Basic characteristics of the enrolled studies.

Study	Exposure	Period	Study design	Location	Major ethnicity	Age	Groups	Positive findings	NOS
Selevan, 2000	PM10, TSPs, SO2, CO, Nox	1993-1994	Cross-sectional	Czech	Caucasian	18	Residents in urban or rural areas	Lower progressive motility, total motility, normal morphology rate, and chromatin structure	8
De Rosa, 2003	Traffic pollutants	2000-2002	Cross-sectional	Italy	Caucasian	23-62	Workers at motorways or offices	Lower total motility, progressive motility, concentration, VSL, VCL, LIN, and ALH	6
Rubes, 2005	PM10, PAH, SO2, NOx	1995-1997	Longitudinal	Czech	Caucasian	19-25	Residents in winter and summer	None	9
Guven, 2008	Traffic pollutants	NM	Cross-sectional	Turkey	Caucasian	;	Workers at motorways or offices	Lower normal morphology rate, concentration, progressive motility	6
Boggia, 2009	Traffic pollutants	2000-2004	Cross-sectional	Italy	Caucasian	23-57	Workers at motorways or offices	Lower total motility and progressive motility	6
Rubes, 2010	PM2.5, SO2, NO, CO, O3, PAH, Benzo	2007	Longitudinal	Czech	Caucasian		Residents in winter and spring	Lower total motility and DFI	9
Calogero, 2011	Traffic pollutants	NM	Cross-sectional	Italy	Caucasian	20-47	Workers at motorways or offices	Lower normal morphology rate, concentration, total sperm count, progressive motility, and DFI	6
Zhou, 2014	PM10, SO2, NO2	2007	Cross-sectional	China	Asian	20-40	Residents in urban or rural areas	Lower normal morphology rate, VSL, VCL, and VAP	8
Wu, 2016	PM10	2013-2015	Cross-sectional	China	Asian		Residents with different PM exposure	Lower concentration and total count	9
Liu, 2017	SO2	2013-2015	Cross-sectional	China	Asian		Residents with different PM exposure	Lower total count, concentration, progressive motility, and total motility	9
Lao, 2018	PM2.5	2001, 2004	Cross-sectional	China	Asian		Residents with different PM exposure	Lower normal morphology and higher sperm concentration	8

ALH: amplitude of lateral movement of sperm head; DFI: DNA fragmentation index; LIN: linearity of sperm motion; NM: not mentioned; NOS: Newcastle-Ottawa Scale; TSPs: PM-total suspended particulates; VCL: sperm curvilinear velocity; VSL: sperm linear velocity.